This study focuses on the morphology of the palatoquadrate, and its relationship with feeding strategies in sharks. This is the first study on a large scale, comparing 87 different species (143 specimens, 1-3 per species covering 27 families and 8 orders). All specimens were scanned using computed tomography techniques, and 3D images were created using the software package Mimics. Variance in morphology was quantified by placing 14 landmarks based on their functional homology using Landmark Editor. The results were processed in MorphoJ for further statistical analysis. The variance in palatoquadrate morphology was quantified using principal component analyses. Species were categorized into one of four diet groups based on literature: fish and cephalopod eaters, hard benthos, soft benthos, and generalists. To correlate the morphological variance with the diet, canonical variance analysis was performed on PCA results with diet as a priori group. The results from the CVA gave a significant difference in shape of the palatoquadrate between feeding guilds. Feeding guilds were strongly correlated with phylogeny, but within phylogenetic groups consistent differentiation according to feeding guild was found by creating a phylomorphospace. The results from the phylomorphospace showed that there is a phylogenetic signal which needs to be taken into account. However, as the previous results showed comparing species with a higher degree of relatedness, most of the variation in morphology is likely attributed to adaption to feeding strategies. Studying the variation in morphology showed that fish and cephalopod eating sharks have elongated jaws with a higher process on the anterior end for muscle attachment, suitable for ram feeding. Hard benthos eaters have shorter, robust jaws for crushing prey, as well as a higher bridge on the anterior end. Soft benthos eaters have jaws suitable for suction feeding, as they have short jaws, smaller dentition, and a larger orbital articulation process.
|Publication status||Published - 2014|
|Event||European Elasmobranch Association 2014 Scientific Conference - Leeuwarden, Netherlands|
Duration: 7 Nov 2014 → 9 Nov 2014
|Conference||European Elasmobranch Association 2014 Scientific Conference|
|Period||7/11/14 → 9/11/14|